Rising temperatures may pose a challenge to the long-term food security of China, the world's most populous country, according to a recent official report evaluating climate change. China's output of major crops, including rice, wheat and corn, could fall by up to 37 per cent in the second half of this century if no effective measures are taken to curb greenhouse gases in the coming 20 to 50 years, according to the report. Global warming will negatively impact China's ecological, social and economic systems, especially farming, animal husbandry and water supply, with some damage irreversible, said the report. The...